The present invention is directed to a circuit board having a plurality of power semiconductors, such as metal oxide semiconductor field effect transistors (MOSFETs) for handling electrical power. As is known, each MOSFET is associated with a control circuit and resistor elements. The present invention separates these three components into at least two sections on the circuit board. Thus, the MOSFETs are mounted as separate units directly to the board in a power section, with the control circuits mounted in a control section.
In the prior art, circuit boards for handling power typically include a plurality of MOSFETs. These MOSFETs have historically been mounted to a board substrate as a number of preassembled units. Each of the preassembled units includes the control circuit, as well as the MOSFET. Further, the subassemblies have typically been provided with separate, ceramic layers carrying the MOSFET and the control circuit. Resistors are sometimes mounted between the two ceramic layers. An outwardly extending mount structure attaches all of these components as a preassembled unit to the board substrate.
The prior art circuit boards had undesirably high assembly time and cost due to the various steps required to form the subassembled unit. Further, preassembled units require more space than would be desirable, and thus reduced the available “density” of MOSFETs per given area of circuit board.